1，現象：

運行時錯誤，后臺出現空指針異常； 代碼沒有任何編譯錯誤，operationbinding返回的result是null。

前臺出現PPR錯誤，編號從1開始增加：

Servelet Exception during PPR, #1 Servelet Exception during PPR, #2 Servelet Exception during PPR, #3 ... Servelet Exception during PPR, #n

部分log信息如下：

后臺：

<ActionListenerImpl><processAction> java.lang.NullPointerException javax.faces.el.EvaluationException: java.lang.NullPointerException at org.apache.myfaces.trinidad.component.MethodExpressionMethodBinding.invoke(MethodExpressionMethodBinding.java:51) at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) at org.apache.myfaces.trinidad.component.UIXCommand.broadcast(UIXCommand.java:190) ...... at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201) at weblogic.work.ExecuteThread.run(ExecuteThread.java:173) Caused by: java.lang.NullPointerException at cn.com.rpt.bean.Login.doLogin(Login.java:67) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.sun.el.parser.AstValue.invoke(AstValue.java:157) at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:283) at org.apache.myfaces.trinidad.component.MethodExpressionMethodBinding.invoke(MethodExpressionMethodBinding.java:46) ... 43 more <RegistrationConfigurator><handleError> Server Exception during PPR, #3 javax.servlet.ServletException: java.lang.NullPointerException at javax.faces.webapp.FacesServlet.service(FacesServlet.java:277) at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227) at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125) at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:300) ...... Caused by: javax.faces.el.EvaluationException: java.lang.NullPointerException at org.apache.myfaces.trinidad.component.MethodExpressionMethodBinding.invoke(MethodExpressionMethodBinding.java:51) at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) ...... ... 35 more Caused by: java.lang.NullPointerException at cn.com.rpt.bean.Login.doLogin(Login.java:67) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ...... ... 43 more

或者：

<2011-8-9 下午04時39分29秒 CST> <Error> <HTTP> <BEA-101020> <[ServletContext@31577370[app:NEUADFFRS module:NEUADFFRS-FRSUI-context-root path:/xxxx-context-root spec-version:2.5]] Servlet failed with Exception oracle.jbo.PersistenceException: JBO-26000: 加載定制項時出現一般性異常錯誤。 at oracle.jbo.mom.MOMParserMDS.parse(MOMParserMDS.java:252) at oracle.jbo.mom.MOMParserNonMDS.readAndParse(MOMParserNonMDS.java:71) at oracle.jbo.mom.DefinitionContextStandard.readAndParse(DefinitionContextStandard.java:237) at oracle.jbo.mom.DefinitionManager.loadDefElement(DefinitionManager.java:1170) at oracle.jbo.mom.DefinitionManager.loadLazyDefinitionObject(DefinitionManager.java:946) Truncated. see log file for complete stacktrace Caused By: oracle.mds.exception.MDSRuntimeException: MDS-00068: 找不到以下對象的類型定義: 名稱空間 = http://xmlns.oracle.com/bc4j, 本地名稱 = LABEL, 文件位置 = /cn/com/xx/vo/XxxVO.xml at oracle.mds.internal.model.parse.MDSNodeParser.findMMElement(MDSNodeParser.java:322) at oracle.mds.internal.model.parse.MDSNodeParser.createModelNode(MDSNodeParser.java:603) at oracle.mds.internal.model.parse.MDSNodeParser.startElement(MDSNodeParser.java:240) at oracle.mds.internal.parsefwk.TreeBuilder$Handler.startElement(TreeBuilder.java:298) at oracle.xml.parser.v2.NonValidatingParser.parseElement(NonValidatingParser.java:1328) Truncated. see log file for complete stacktrace >

前臺界面：

java.lang.NullPointerException For more information, please see the server's error log for an entry beginning with: Server Exception during PPR, #3
2，解決方案

檢查JDeveloper版本，我出現該情況的時候，使用的是JDeveloper 11.1.1.3.0，而同事用了JDeveloper 11.1.1.4.0，創建了VO對象等。
手去修改VO對象的版本號，11.1.1.59.23-->11.1.1.56.60，去除VO中錯誤代碼。

重新運行，OK。

TROUBLESHOOTING: Servelet Exception during PPR, #1...#n